Jack Johnson at the Bonnaroo Music & Arts Festival on Saturday, June 15, 2013, in Manchester, Tenn.

Jack Johnson opened his set at Bonnaroo Saturday night with a dedication to Mumford and Son's Ted Dwane and his bandmates.

"I wish we could all be here playing music together right now," he said.

Johnson was a last-minute replacement for headliner Mumford and Sons, which had to cancel their appearance due to bassist Dwane's medical condition.

In the crowd there was a mixture of disappointment and happiness.

"I'm sad, but I'm happy because it's Jack Johnson," said 22-year-old Leigh Parsons as she waited in the glow of the bright stage lights for the show to begin. "I was like, 'Ohhh ... Yay.' ...
"In my opinion it's an upgrade."